Hi! Welcome to the group. If you go to Rockler.com, they have a deal
right now where you get their Adirondack chair plan free if you sign up
for their email newsletter. You might have to click 'reload' a few
times on your browser, because the chair plan is one of 3 or 4 ads that
cycle through when the page loads (right-hand side of page). If you
don't have experience with them yet, Rockler is a great woodworking
supply company in general.
I don't know if Rockler's plan is better than other free plans you can
find on google, but I like to look at a few plans (if available) and
take things I like from each one before carefully planning my final
version of whatever I'm making.
There is also a fairly detailed Adk chair plan at Popular Mechanics
Also, you can try searching google groups - a few recent threads
suggest that Norm's adk chair plans are the most comfortable (that's
Norm of New Yankee Workshop - check out the link in the post above),
while Jake's chair isn't as comfortable or good looking.
I haven't built any of these - I'm just passing along things I've seen
recently while browsing.
In my experience, the free plans you can find all over the web are
usually not very detailed, not step by step, or maybe just "shop
drawings". When you pay for plans, or download the "weekly special" or
whatever from various woodworking catalogs or magazines, there are
often more detailed cut lists, diagrams, and step-by-step photos and
descriptions. Of course there are lots of exceptions both ways here.
Hope this is helpful - good luck and have fun with your project,